Pathophysiology of Free Cortisol in Plasma

Brien, T. G.

doi:10.1111/j.1749-6632.1988.tb48858.x

Cited by 11 publications

(10 citation statements)

References 27 publications

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“…As cortisol has been suggested to play a role in detecting OR and OTS [19,31] we found it necessary to study the effects on cortisol levels of exogenous and endogenous hormonal profiles in physically active women. Our results of markedly increased cortisol levels in OC users have also been demonstrated in other non-sporting female cohorts when women received estrogen or were pregnant [2,8,10,14,47,48] [8,10,47] or used OC [2,14,48]. Cortisol was increased in the previous studies due to both triphasic OC [2] and mono phasic OC [14] use, though the women in these studies were not physically active.…”

Section: Impact Of Season and Oral Contraceptive Use On Cortisol Levesupporting

confidence: 50%

“…Cortisol is commonly reported both as total cortisol and free cortisol. It is known that cortisol exists in plasma in three forms, 80-90% bound with high affinity to CBG, about 10-14 % associated with albumin and about 6-10% in unbound form as free cortisol [8,9,10,12,23,26,34,39,42]and it is suggested that only the free cortisol is biological active [8,10,12,36,42].There are several techniques for measurements and calculations of free cortisol but many of them are not suitable for routine laboratory use [5,11,12,15,17,43]. In this study we used a modified model (cortisol/CBG ratio) of the Free Cortisol Index [5].In our study we found no seasonal variations in the calculated cortisol-to-CBG ratio neither in OC users nor in non-users.…”

Section: Limitations and Methodological Aspectsmentioning

confidence: 99%

“…Hence the influence of both the exogenous and the endogenous hormonal profiles on athletic performance should be investigated [41]. An administration of estrogen, as in women with OC use, can cause increase in total plasma cortisol [8,10], and in free cortisol [39]. Coolens et al [12] showed elevated cortisol levels in estrogen treated women, but unbound cortisol levels were similar to the control group.…”

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confidence: 99%

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Physiology of Blood Components in Wound Healing: an Appreciation of Cellular Co-Operativity in Platelet Rich Plasma Action

Parrish¹

2017

JESO

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Open Access Research Articletraining sessions and periods, [19,30,31]and the time needed for recovery is considered to be much longer compared to OR [22]. Because of both gradual onset of OR and gradual transition from OR to OTS, it is important to detect symptoms at an early stage [30].No single, specific, and reliable biological parameter to diagnose OR and OTS at an early stage has been found, and there has been only little improvement in recent years in developing tools suitable for diagnostics [1,22,30,45]. Hence, physicians and trainers are looking for new ways to diagnose and monitor athletes that may be at risk [1,28].The resting cortisol level has been suggested to play an interesting role in detecting OR and OTS since it is thought to indicate stress [19,31]. However, levels of resting cortisol has been both increased, decreased and unchanged in over trained athletes, and the research has mainly been performed on male athletes [3,18,25,32,33,44,46].Female athletes have become a common part of the sports environment [21]and since most research has been performed on male athletes, studies on female athletes are warranted. Oral Contraceptive (OC) use is prevalent in female athletes [21,41] and the impact of OC use and non-use on cortisol levels in female athletes are not well studied. Hence the influence of both the exogenous and the endogenous hormonal profiles on athletic performance should be investigated [41]. An administration of estrogen, as in women with OC use, can cause increase in total plasma cortisol [8,10], and in free cortisol [39]. Coolens et al. [12] showed elevated cortisol levels in estrogen treated women, but unbound cortisol levels were similar to the control group. Since estrogen could influence cortisol levels, studies on female athletes should include both OC users and nonusers. Moreover, since seasonal periodicity in various endocrine functions can occur [24,37] it seems crucial to determine if this may effect cortisol levels differently in OC users and non-users. As the role of cortisol in indicating stress is multifaceted and complex there is a need to investigate both seasonal variation and impact of oral contraceptive use on cortisol levels to evaluate if cortisol could be used to diagnose and monitor female athletes that may be at risk to develop OR and OTS. AbstractWhen athletes optimize their physical performance, an imbalance could occur between the strain of training, time for recovery and the athlete's individual tolerance of stress that could lead to overreaching and overtraining syndrome. Cortisol has been suggested to be a biological, diagnostic marker to detect overreaching and overtraining syndrome, since it is thought to indicate stress. This study aimed to provide normative data on cortisol levels, hence investigate seasonality and impact of oral contraceptive use to elucidate if cortisol could be used as a diagnostic marker to detect overreaching and overtraining syndrome in female athletes. The women, divided in two groups, oral contraceptive users (n = 15) and ...

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Section: Impact Of Season and Oral Contraceptive Use On Cortisol Levesupporting

confidence: 50%

Section: Limitations and Methodological Aspectsmentioning

confidence: 99%

mentioning

confidence: 99%

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Physiology of Blood Components in Wound Healing: an Appreciation of Cellular Co-Operativity in Platelet Rich Plasma Action

Parrish¹

2017

JESO

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“…Since in general only the free hormone fraction is considered to be biologically active (19,20), our data suggest that during the acute phase response free serum cortisol measurement is biologically more appropriate compared to the measurement of total cortisol. We decided to study cortisol protein binding during acute phase response in patients undergoing elective cardiac bypass surgery with extracorporeal circulation because this well standardized procedure induces extensive stress and systemic inflammatory response (as demonstrated by very high CRP concentrations), and individual baseline samples can be taken in a non-stressed state before the patient is transferred to intensive care; this is not the case, for example, in a heterogeneous population of intensive care patients with septic shock.…”

Section: Discussionmentioning

confidence: 95%

“…The algorithm described by Coolens et al (17) applied in other studies (10,12) takes into account the binding characteristics of CBG and is applicable by use of standard spreadsheet software; this calculation, however, is simplified in that the concentration of albumin and sexhormone-binding globulin (as other important cortisol-binding proteins), and competing steroids as cortisone are not incorporated. Conclusive calculation of free serum cortisol concentrations taking into account the latter variables, however, is not generally applicable, since it leads to complex equations which have to be solved by numeric procedures for which no software is commercially available (11,19,22). Interestingly, calculations that incorporate the binding characteristics of CBG and cortisol -both in a simplified form (17) and by computer simulation (22) -predict a non-linear rise in bioactive free serum cortisol with increasing total serum cortisol concentrations, even at constant CBG concentrations and within the physiological range of circadian variation of cortisol concentrations; a simple "free cortisol index" (13,21) fails to display this and should not be used.…”

Section: Discussionmentioning

confidence: 99%

Free Serum Cortisol during the Postoperative Acute Phase Response Determined by Equilibrium Dialysis Liquid Chromatography-Tandem Mass Spectrometry

Vogeser¹,

Groetzner²,

Küpper³

et al. 2003

Clinical Chemistry and Laboratory Medicine

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In severely ill patients low concentrations of the corticosteroid binding globulin are typically found; the aim of this study was to quantify directly free bioactive cortisol concentrations in the sera of postoperative cardiosurgical patients. Serum samples of 12 consecutive patients undergoing aortocoronary bypass surgery taken preoperatively and on the postoperative days 1 to 4 were analyzed. Total serum cortisol was quantified using liquid chromatography-tandem mass spectrometry with an on-line sample extraction system and tri-deuterated cortisol as the internal standard, and free serum cortisol was measured after over-night equilibrium dialysis. Whereas on the first postoperative day, the median total serum cortisol concentration was approximately two-fold increased compared to preoperative samples (preoperatively, 245 nmol/l (interquartile range (IQR) 203 -293 nmol/l); first postoperative day, 512 nmol/l (IQR 410 -611 nmol/l)), median dialyzable free cortisol concentration was almost seven-fold increased (preoperatively, 14.2 nmol/l (IQR 10.9 -20.7 nmol/l); first postoperative day, 98.3 nmol/l (IQR 81.3 -134 nmol/l)). On the fourth postoperative day, median free cortisol was still significantly increased compared to baseline sampling (p < 0.05), whereas median total cortisol was not. A median of 5.7% (IQR 5.4 -7.0%) of total cortisol was found as free cortisol on the preoperative day, 21.2% (IQR 18.9 -23.5%) on the first postoperative day and 10.5% (IQR 9.8 -14.0%) on the fourth postoperative day. It is concluded that during the postoperative period the freeto-bound ratio of cortisol is highly variable and that during the acute phase response direct quantification of free bioactive cortisol concentrations seems to be biologically more appropriate than the measurement of total cortisol concentrations. Clin Chem Lab Med 2003; 41(2):146 -151

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Biological activities of the shrub Salsola tuberculatiformis Botsch.: Contraceptive or stress alleviator?

2003

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Plants belonging to the genus Salsola (Family: Chenopodiaceae) are common in the arid and semiarid regions of our planet with no less than 69 different Salsola species found in Namibia and the Republic of South Africa. This genus is used as a traditional medicine and aqueous extracts of Salsola have been used by Bushmen women as an oral contraceptive. Ingestion of the Namibian shrub Salsola tuberculatiformis Botsch. by pregnant Karakul sheep leads to prolonged gestation and fetal post-maturity and, as a result, the pelts of the new-born karakul lambs are worthless. This initiated an investigation into the active agents in the plant, using the terminal enzyme in adrenal corticosteroidogenesis, cytochrome P450-dependent 11beta-hydroxylase (P450c11), as a bioassay. Although the active fraction, S2, was extremely labile, partial structure determination suggested the presence of synephrine and a highly reactive aziridine. Therefore a more stable analogue, 2-(4-acetoxyphenyl)2-chloro-N-methylethylammonium-chloride (compound A), was synthesised, which, like the active plant extracts, inhibited adrenal steroidogenesis and acted as a contraceptive. In addition, compound A was stabilised by interaction with steroid-binding globulins in plasma thus enhancing biological activity in vivo. These findings provided explanations for the complex biological effects of the shrub as well as a new insight into the mode of action of chemically labile plant products in vivo.

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Pathophysiology of Free Cortisol in Plasma

Cited by 11 publications

References 27 publications

Physiology of Blood Components in Wound Healing: an Appreciation of Cellular Co-Operativity in Platelet Rich Plasma Action

Physiology of Blood Components in Wound Healing: an Appreciation of Cellular Co-Operativity in Platelet Rich Plasma Action

Free Serum Cortisol during the Postoperative Acute Phase Response Determined by Equilibrium Dialysis Liquid Chromatography-Tandem Mass Spectrometry

Biological activities of the shrub Salsola tuberculatiformis Botsch.: Contraceptive or stress alleviator?

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